Fusible link



M. K. HOPKINS.

FUSIBLE LINK.

"memo" FILED APR. 23. me.

1,356,919. Pam md Oct. 26,1920.

UNITED STATES PATENT OFFICE. a

MOBTONK. HOPKINS, OF CHICAGO, ILLINOIS, ASSIGNOR T0 JOHN L. KENNEDY, OF

' CHICAGO, ILLINOIS.

FUSIBLE LINK.

To all whom it may concern:

Be it known that I, MORTON K. HOPKINS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Fusible Links, of which the following is a description.

My invention belongs to that eneral class of devices known as fusible links, which under normal conditions are adapted to securely connect coiiperating parts or mechanisms, but under abnormal conditions will release to allow the parts to separate. Such devices are used for many purposes, but are particularly desirable and very generally used in connection with automatic sprinkler heads, and my improved link is peculiarly adapted for that use, but obviously may be used wherever found desirable.

The invention has among its objects the production of a device of the kind described that is simple and economical in construction, and thoroughly efiicient and satisfactory in use.

To this end, my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and more particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like or corresponding parts,

Figure 1 is a face view of myimproved link assembled;

Fig. 2 is an edge view of the same before the solder is applied;

Fig. 3 is a sectional view on line 33 of Fig. 1;

ig. 4 is a transverse sectional view on line 44 of Fig. 1;

Fig. 5 is a sectional view similar to Fig. 3, enlarged to more clearly show the operating portion of the device; V

' ig. 6 is a vertical central sectional view, illustrating the operation asthe parts are separated;

Fig. 7 is an inside face view illustrating a slight modification; and

Fig. 8 is a central vertical section on line 99 of Fig. 7 when the latterand associated parts are assembled. 7 7

Referring to the several drawings, 12 are coiiperating mating plates adapted to be placed face to face with the connecting loops extending in opposite directions. One of the Specification of Letters Patent.

Patented Oct. 26, 1920.

Application filed April 23, 1919. Serial No. 292,142.

plates, as 1, has a pocket 3 formed therein, which at its forward end, as shown in Figs. 1 to 6, is slightly depressed to receive an anti-friction roller 4 extending transversely the same. The approximate wall of the pocket or depression is preferably inclined as at 13. The opposite plate has a coiiperating recess 6 formed therein substantially registering with the recess 3, the two providing for the reception of a key member 7. The key has a thickened portion as at 8, substantially to the extent that it will loosely fill the cell formed between the two plates at that point. An extending thinned portion 9 extends over the anti-friction roller 4, and

lies upon the inner wall ofthe plate as at 10. A shoulder 11 formed between the thickened portion and the thin or extending tongue 9 of the key 7, rests back of the anti-friction roller 4:, as clearly shown in Figs. 3 and 5, and is preferably provided with an Outwardly inclined part 5. In the form of plate shown, the two plates are stamped from suitable metal, the formation of the cell 3 being indicated on the opposite side of the plate 1. Suitable studs 12 are preferably provided upon the meeting faces of the plates so as to slightly space the two and permit the even distribution of the solder therebetwcen. When the parts are assembled and in use, the pull is in the direction indicated by the arrows in Figs. 2, 3, 6 and 8.

' in assembling the plates, the anti-friction roller 4 is dropped into position, and the key 7 placed thereon, with the shoulder 11 back of the roller, the roller and key loosely but somewhat snugly fitting the cell or pocket thus formed. The other plate is then placed in position and the whole secured together by a suitable quality of solder.

It will be seen that with the pull in the direction indicated by the arrows, the loosening of the solder will cause the shoulder 11 to ride over the anti-friction roller 4, the front end 9 of the key bearing upon the face of one plate, while the rear wall of the other plate engages the corner of the key, as clearly shown in Fig. 6. This action causes the forcible and instantaneous separation of the two plates.

In the form shown in Figs. 7 and 8, the same construction is found, with the exception that the anti-friction roller 4 is not seated in a depression in the cell. The rear wall of the cell, as at 13, is inclined as before to provide but a slight retaining corner, and the coiiperating face of the key as at 14 is also inclined, the two being so constructed as to provide positive engagement between the parts, though slight. Upon the solder releasing, the rear wall of the cell in the plate 2 will engage the corner 15 of the key, serving to slightly lift the same, when the inclined face on the key will ride over the roller and the key will. slip over the wall, the front extension 9 operating in the same manner as is shown in Fig. 6. The action of the roller is slightly less restricted in the latter form than in the former.

One of the difliculties of a fusible link used for this purpose is caused by corroding between the meeting edges of the plate about the margin. Also in some cases calciinine gathers upon the plates and interferes with their proper action. To guard against the objections above noted, I prefer to offset the plates in relation to each other to provide an extending margin, as clearly shown in Figs. 4 and 7. The width of this extending margin may be varied as desired,.

but it preferably extends clear about the outer edges of the links, as well as at all exposed points, as at the opening 17 and the cooperating indentation 18. This may be readily accomplished by slightly offsetting ing one plate with relation to the other, as indicated in the several figures.

The entire device as thus described possesses the necessary positive engagement of the parts to reliably sustain the strain in the pulling direction under all. normal conditions, and at the same time, when the solder softens sufliciently to release the parts. they are quickly and reliably disengaged to permit the separation of the connected parts held together by the link.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same Without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described, or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. In a fusible link and in combination, cooperating mating parts adapted to be placed face to face and constructed to provide a key way between them, an anti-friction device transversely positioned in the key way adjacent to one wall thereof, and a cooperating key adapted to be placed in the key way with a part extending back of and in contact with the anti-friction device, with an extension passing over the anti-friction device and resting upon the wall of the plate beyond the same, whereby upon assembling the parts together with suitable solder, they will be firmly retained in position, but upon melting the solder, they will be quickly and positively disengaged.

A fusible link comprising coiiperating mating plates adapted to be placed face to face" and constructed to provide a key way between them, an anti-friction roller transversely positioned in the key way adjacent to one wall thereof, in combination with a coiiperating key adapted to be placed in the key way with a part extending back of and in contact with the anti-friction device, with an extension passing over the same and resting upon the wall of the plate beyond it, the contacting wall of the cell with the anti-friction device and of the shoulder of the key contacting therewith being inclined to facilitate the riding of the key over the anti-friction device.

3. In a fusible link and in combination, cooperating mating parts adapted to be placed face to face and constructed to provide a key way between them, said key Way near one wall thereof being depressed transversely to receive an anti-friction roller, an anti-friction roller adapted to be placed in said depression, a coiiperating key adapted to be placed in the key way, provided with a part extending back of and in contact with the anti-friction roller, with an extension passing over the anti-friction roller and resting upon the wall of the plate beyond the same, said key being provided at its meeting point with the anti-friction roller with an inclined face, facilitating the ready riding of the key over the roller.

at. In a device of the kind described and in combination, coiiperating mating parts adapted to be placed face to face and constructed to provide a key way between them, the key way being so positioned that when the parts are assembled said plates will be offset slightly in relation to one another, permitting the edges to project beyond one another to provide. a solder channel, antifriction means arranged transversely within the key 'way adjacent to one wall thereof, a cooperating key adapted to be placed in the key way with a part extending back of and in contact with the anti-friction means, with an extension passing over the anti-friction means and resting upon the Wall. of the.

plate beyond the same, the contacting wall of the key way with the anti-friction means being inclined to facilitate the ready riding of the key over the anti-friction means.

In testimony whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

MORTON K. HOPKINS. lVitnesses:

JOHN W. HILL, CHARLES I. COBB. 

